Defending Tour de France champion Bradley Wiggins said Thursday he was shocked by the mountain of evidence compiled against Lance Armstrong, calling it “jaw-dropping” that as many as 11 former teammates testified against the sporting icon.

But Wiggins, who finished fourth to the American’s third in the 2009 race, said he wasn’t surprised by the conclusion of the U.S. Anti-Doping Agency: that Armstrong cheated his way to a record seven Tour championships by using banned substances and deftly evading tests that would have exposed him.

But according to several marketing experts, Armstrong may well lose his handsome corporate backing from Nike, Anheuser-Busch, Trek and others once existing contracts expire. And given the damning details USADA has compiled — the first-hand accounts that he not only used banned substances but also demanded fellow riders use them, too, in support of his quest for titles — Armstrong likely won’t forge any new corporate deals.

“If you’re a corporation and you’re selling truth and you’re selling performance — and not just the outcome of performance, but clean performance in a competition that’s based on rules and rules and values — I think you’ve got a problem on your hands,” said David Carter, executive director of the Sports Business Institute at Southern California, of the companies with ties to Armstrong.

“They may let those contracts lapse, rather than cut him immediately. They may choose not to feature him [in advertising or promotional campaigns] until the contracts run out. But for anyone to align with him now, it wouldn’t make a lot of sense until the smoke clears.”

Paul Swangard, managing director of the University of Oregon’s Warsaw Sports Marketing Center, said he suspects Armstrong’s future marketability is “forever reduced” by the disclosures in the USADA document, which include threats against those in position to testify against him.

“Brands forge partnerships with athletes for the benefit of shared equity,” Swangard said, “and Lance as a brand is probably just not worth the trouble for anyone who is not currently attached to him.”

Although Armstrong’s unprecedented streak of Tour de France victories has been dogged by allegations of cheating for years, the events of the past two months represent a stunning fall for an athlete who raised cycling’s profile globally and transcended his sport.

The weight of evidence USADA presented this week to the International Cycling Union, which governs the sport, was overwhelming in its detail and specificity. And it was made more credible by the athletes who came forward, such as George Hincapie and Levi Leipheimer, who confessed their own part in doping while providing information about Armstrong’s role in what USADA characterized as a team-wide doping conspiracy. They’re among five cyclists who will serve a six-month ban as a result, a relatively light punishment in exchange for their testimony.

That said, donations to the Lance Armstrong Foundation, which has raised $480 million on behalf of cancer victims since it was founded in 1997, are running at almost twice normal levels since the cyclist was banned from competition in August, according to Katherine McLane, the foundation’s vice president for communications and external affairs. Moreover, the number of patients and families seeking help negotiating treatment options, insurance and other matters is up 15 percent in that time.

“These issues have been in the news not just since August 24th but for many, many years,” McLane said. “The Lance Armstrong Foundation has existed within this climate, so it’s nothing new for us and nothing new for our corporate sponsors. . . . We have seen no loss of support on a constituent level of anything like that.”

If it seems like a paradox, it makes sense to Ashley McCown, president of Solomon McCown & Company, a Boston-based public-relations firm that specializes in crisis communications.

Armstrong is “a brand unto himself,” in McCown’s view, because his athletic achievements have been intertwined with his victory over testicular cancer and his 15-year crusade to use the platform of his sporting triumphs to help others battling cancer.

So McCown wasn’t surprised to find so much fervent support for Armstrong in surveying social media in the wake of the release of the USADA report.

“He won the Tour de France after he beat cancer,” McCown noted. “You put those two together, and it’s phenomenal. It’s inspirational to so many people. . . . People have separated the personal choices he has made around doping from the good work he has done for cancer victims.”